Radial piston type pump



March l, 1955 J. N: HEATER RADIAL PIsToN TYPE PUMP INVENTOR.

March 1, 1955` J NHEATER 2,703,054

RADIAL PISTON TYPE PUMP Filed May 24, 1952 5 Sheets-Sheet 2 6. o 8 i gg March 1, 1955 Filed May 24, 1952 J. N. HEATER RADIAL PISTON TYPE PUMP jill IM/ENTOR.`

@703.4154 RADIAL PrsroN TYPE BUMP- Jt?hn N. Heater, Cincinnati, hio, assigner to American 'reey Application May 24, 1952, Serial No. 289,859,v

6 Claims.

Vr[his invention relates to hydraulic pumps and more particularly to a novel purnp of the type wherein plungers are actuated by rotating 'them'aga'inst a'nonconcentric surface which causes the plungers Vto move' into their chambers on discharge 'stroke and pe'rmits'the plungers to move out of their' chambers on suction stroke under the centrifugal force develope'd by their rotation;

A primary object of the invention is to4 devise a pump such as above described wherein commercial bearings m'ay be usedthroughoutthe device to simplify manufact'ure thereof. Another object of the invention is to balance internal hydraulic forces within`the pump thereby simplifying its construction. i

A further object of the invention is to aiord a double stroke for each piston on each revolution( thereof,'th ereby permitting the use of smaller pistons, shorter. piston stroke,` greater number of pistons'for a given cross sectional area of the rotor, and higher speed'of4 rotation than heretofore possible in'such pumps.

VA more specic'object of the invention is to devise a pump wherein plunger/s are -mounted within'pump chambers of a rotor which is rotated within a conventional cylindrical antifriction bearing, vthe rotational axis of which intersects and is angularly related to the rotational axis of the plungers when the pump is on stroke, whereby the plungers trace an elliptical path aroundV the inner race o f the antifriction bearing. A further object of the invention is to control the discharge of the pump by rotating the plungerretaining antifriction bearing between a Zero or neutral position at which the bearing and plunger rotor are substantially coaxial and a maximum discharge position, whereat'the bearing axis is at maximum angularity to the. rotor axis. Still another object of the invention is to' reverse delivery of the pump by rotating a portedpintle sleeved within the rotor. Yet another Obeet qt the invention is to coordinate rotation of the pintle with rotation ofthe plungeryrev taining bearing, to minimize hydraulic shock within ythe p nmpduring reversal of delivery thereof;

The foregoing and other objects and advantages of the s invention will become apparent f rtnnl a consideration of the' fllo'wig Specification and accompanying drawings, wherein:

Figure 1 is a vertical sectional View through a nonreversible, constant diseherge'pump embodying the inf vention;

l"Figure 2 is a sectional view on the line 2` `2.ot`l Figf Ure 1;

Figure 3 is a sectional view on `the line of Figure 2; v

Figure 4 is an end view of the pintle taken from the inner` or left extremity thereof :is seen in Figure 1;

Figure 5 is a sectional View taken on the linev` 5,?,5 of Figure 4;

Figures 6-8 illustrate a nonreversible, variable dischargepumpy embodying the invention,j Figure` 6 being a central vertical sectional view through thepump, Fig.- ure`^7`being a sectional view through the pintle on line 7,-"f7 of Figure 6,v andv Figure 8` being a fragmentaryseotional view through the antifriction bearing and one of its v-trunnions `on the' plnefindicated` by line. of Figure 6; and A' Figures 9 and l0 illustrate alreversible delivery, Variable discharge purnp embodying theinventio'n, Fi A 9 beig'a central vertical sectional view through Seel Feindes, Charge 111.; a entre@ @if 2,703,054 Patented Mee 1., 1.955

Figure l0 being a sectional View on the line 10 10 of Fi'gre9. "Describing the invention in detail and referring iirst to the embodiment thereof illustrated in Figures l to 5', 'the novel pump comprises a casing generally designatedl t orm'ed of separable segments 2 and 4 with a conventional a'ntifriction bearing unit 6 clamped therebetween,w said unit'comprising inner and outer races 8 and 10 with a plurality of roller bearings 12 conned therebetween. The pump casing segments 2 and 4 are interconnected by any suitable means (not shown) and define an internal chamber`14 within which is positioned a hollow rotor 16 having an axial inlet bore or chamber 18 with a largerdiameter portion 20 at the inner end of the rotor. The rotor chamber portion 20 is connected -to a plurality of bushed pump chambers or passages 22 arranged radially with respect to the longitudinal or rotational axis of the rotor, said chambers containing pistons 24 engageable with the inner race 8 of the antifriction bearing 'under centrifugal force due to rotation of the rotor16 on its longitudinal axis. f

The rotor is supported by lball bearing units 26 and 28 within the casing segment 2 and is provided with the before mentioned axial chamber or suction passage 18 which is connected by radial ports 32 to a suction or inlet port' 34 of the casing 1 The larger-diameter portion 20 of the rotor chamber 18. is `sleeved over a hollow pintle 36 which is xed to the casing segment 4 in any convenient manner as, for example, by a ring 38 keyed o'r press fitted on the pintle and anchored by cap screws 40.

,Thefpintle 36 contains an axial internal discharge or pressure chamber or passage 42 which is arrangedcoaxially with respect to the rotor passage'lS Vand is conneted as best seen in Figures 2 and 4 to diametrically opposedl arcuate notches 44 in the outer diameter of the pintle 36; and the pintle also comprises diametrically opposed notches 46 which are interconnected by. a groove 48across the inner ,end of the pintle 36 as best seen in Figures 4 and 5.

It will be understood from a consideration of Figures 1 and 3 that the antifriction bearing unit 6 is arranged diagonally with respect to the rotational axis of the race 8, so that the rotational axis of the race 3 intersects and is angularly related to the rotational axis of the rotor 16, whereby the plungers 24 traverse an elliptical path along the inner periphery of the cylindrical race 8 against which they"are urged by centrifugal force during rotation of thel rotor by any convenient actuating means (not shown) connected to the outer or left end of the rotor as seen inFigure 1.

The'elliptical path traced by the plungers 24 along the .inner surface of the inner race 8 is best seen in the cross sectional view of Figure 2 wherein it will also be noted thatfthe notches 44 and 46 divide the outer periphery of ,the` pintle 3,6 into quadrants, the notches being spaced by uninterrupted segments of the pintle 36 delining lands between the` notches, Thus it will be understood that during' a single rotation of each plunger 24 it pumps onge into eachvdischaige notch 4 4 of the pintle 36 and sucks once from each suction notch 46 of the pintle, the land` being aligned with the longv and short axes of the ellipse. traced v byV the pistons 24.

nReferring now to Figures 6 to 8, an hydraulic p ump isillustrated wherein the above described invention is corn 'inedY with novel means for varying the discharge raA` the pump; and parts of the modification corre. spA lIrdilglgfto those of AFigures l to 4 areidentied by corresponding numerals.

In the modication, the suction pintle notches 46 are connected by pintleports50 to an annular suction chamf ber52 'of 'the pump casing I, and the discharge pintle notches 44A are similarly connected to an annular diseharge' Chamber 5.4 0f the Pump. Gesine The Sueden chamber 52fis connected to a suction port 56 of the pump casing, the discharge chamber 54 is connected toa similar' discharge port (not shown); therebyV ac :cornrnm4 dating flow ofV hydraulic fluid from the suction chamber; 5 4 into the, suction'notches 46, and accommodating flow of fluid from the discharge notches'44 intofthedischarge,

Means for varying the discharge rate of the pump are provided in the form of a piston i6 connected by a piston rod 60 to the antifriction bearing unit 6 which is illustrated in Figure 6 as a ball bearing unit as distinguished from the roller bearing unit of Figures 1 to 3. Also as seen in Figure 6, the antifriction bearing unit 6 is illustrated in a position affording maximum discharge of the pump, and is rotatably mounted in the casing ll by a pair of coaxial trunnions, one of which is shown at 61 in Figure 8. lt will be understood that rotational movement of lthe bearing unit 6 on its trunnions 61 from the position illustrated in Figure 6 to a position whereat the plane of the bearing 6 is perpendicular to the rotational axis of the rotor 16, so that the race 8 and rotor 16 are substantially coaxial results in approximately zero discharge, inasmuch as the pistons 24 under such conditions trace a substantially circular path along the inner perimeter of the cylindrical race 8.

The modiiication illustrated in Figures 6 to 8 embodies means in the form of the piston 58 to accomplish such movement of the antifriction bearing unit 6 for the purpose of regulating discharge of the pump between Zero and maximum; and it will be understood that if desired any other suitable means such as a hand operated screw may be substituted for the piston 58. However, in the illustrated embodiment o'r' Figure 6, the piston 50 is combined with control means for automatically regulating discharge of the pump to a predetermined value.

These control means as shown in Figure 6 are associated with the piston SS which is provided with a head 62 defining advance and pullback chambers 64 and 66 within the pump casing l. The pullback chamber 66 is connected by a pressure port 63 to the discharge or pressure port (not shown) of the pump, whereby upon development of a predetermined pressure in said port 68, pressure uid therein acts upon a piston 70 slidably fitted within a complementary bore 72 of the pump casing and actuates said piston to the right against the resistance of an adjustable spring 74 compressed against another piston 76 having a closed end abutting a smaller-diameter end of the piston 70 which is hollow to accommodate flow of hydraulic fluid from end to end thereof.

Thus as the piston 70 moves to the right in response to predetermined pressure within the port 63, as regulated by the setting of spring 74, the piston 70 closes an exhaust port 78 which normally communicates with a relief or discharge port 80 connected to the suction port 56 of the pump, whereupon further increase of pressure in the port 68 acts on the closed end of the piston 76 urging it out of engagement with the piston 70 thereby admitting pressure fluid to the advance `chamber 64 actuating the piston 58 to the left, whereby the pump discharge approaches zero. Under these conditions the piston 70 is held in closed position with respect to the exhaust port 78, inasmuch as the left end of the piston is of greater cross-sectional area than its right end.

As pump discharge approaches or has reached zero, pressure in the port 68 falls below setting of the spring 74 which urges the piston 76 to the left closing the right end of the piston 70 thereby preventing further movement of piston 76 to the left. Further pressure drop permits the spring 7d to move both pistons 70 and 76 to the position shown in the drawings whereat the advance chamber 64 is opened to discharge through exhaust port 78 and discharge port 80, and pressure in the port 68 acting against the piston head 62 within the pullback chamber 66 moves the piston 5b to the right, thereby increasing the discharge rate of the pump.

It will be noted that the exhaust port 78 is constantly connected to a bleeder discharge port 82 thereby ensuring continual iow of l'luid past the piston 70 upon opening of the piston 76, and thereby affording sensitivity to pressure drops within the port 68 as well as preventing pressure lock in the bore 72 by relieving the diierental areas of the pistons 70 and 76 during the above described operational phases thereof.

In the modication of Figures 9 and 10, means are provided for reversing delivery of the pump and for simultaneously varying the discharge rate thereof to minimize hydraulic shock which would otherwise occur due to reversal of delivery during rotation of the rotor with the pump on full stroke. In this modification, parts corresponding to those previously described are identified by corresponding numerals.

As best seen in Figure 9, a rotor or drive shaft 84 extends entirely through the pintle 36 and is keyed as at 86 to a drive liange 88 which is detachably secured as by screws 90 to the rotor 16. The rotor is slidably fitted over the pintle in substantially uid tight engagement therewith and is rotatably mounted thereon by an antifriction bearing 92.

As in the arrangement of Figures 6 to 8, the pintle discharge notches 44 are connected by ports 50 to an annular discharge chamber 52 of the casing 1; and the pintle suction notches 46 are similarly connected to an annular inlet or suction chamber 54 of the casing. As best seen in Figure 9, the suction or inlet chamber 54 is connected to the suction or inlet port 56, and the discharge chamber 52 is connected to a discharge or outlet port 94.

In the embodiment of Figures 9 and l0, reversal of delivery is effected by rotation of the pintle 36 approxi mately 90 from the position shown in Figure l0, whereupon the suction notches 46 become discharge notches and the discharge notches 44 become suction notches, thereby reversing flow of fluid between the ports 56 and 94. As best seen in Figure l0, if the pintle were rotated to effect reversal of delivery as above described with the piston retaining antifriction bearing unit 6 at maximum angularity to the rotational axis of the rotor 16, as shown in Figure 9,'the lands between the notches 44 and 46 would pass through positions whereat the pistons 24 would compress hydraulic fluid against the lands, thereby resulting in severe hydraulic shock. Such a condition is prevented by means illustrated in a form of a gear train 96 for simultaneously rotating the ybearing unit 6 about its trunnions 61 toward zero discharge position upon rotation of the pintle to reverse delivery of the pump. Thus, upon rotation of the pintle approximately 45 from the position shown in Figure l0, the bearing unit 6 is at zero delivery position, with its inner race 8 approximately coaxial with the rotor 16. Subsequent rotation of the pintle another 45 to complete the reversal of delivery rotates the antifriction bearing unit 6 to maximum discharge position approximately 35 in a clockwise direction from the maximum discharge position illustrated in Figure 9.

The gear train 96 comprises a sun gear 93 integrally formed with or keyed to the pintle 36 and meshed with a plurality of planetary gears 100 rotatably mounted on a ring gear 102. The planetary gears 100 are also meshed with a ring gear 104 fixed in any desired manner as by screws 106 to the casing 1. The rotatable ring gear 102 is meshed with a gear segment 108 formed on an arm 110 which is keyed as at 112 to one of the trunnions 61 which rotatably support the piston retaining bearing unit 6 within the casing 1.

Thus it will be understood that rotation of the pintle 36 to reverse delivery of the pump simultaneously rotates the bearing unit 6 about its trunnion 61 to minimize hydraulic shock within the pump upon reversal thereof with the drive shaft 84 rotating at normal speed, although it will be understood that, if desired, rotation of the drive shaft 84 may be terminated by deenergizing its motor (not shown), whereupon the gear train 96 may be eliminated inasmuch as the pintle 36 may be rotated to reverse the pump without any danger of hydraulic shock, due to the above described causes.

In the illustrated arrangement of Figures 9 and 10, the pintle 36 and piston bearing unit 6 are actuated to reverse delivery of the pump by a handle 114 which may be manually operated or may be connected to any conventional uid or electrically operated shifting motor t' not shown).

I claim:

1. An hydraulic pump comprising a casing, a rotor member having a plurality of substantially radial pump chambers in said casing, pistons slidable in respective chambers, a pintle member supported by the casing and sleeved within the rotor member to afford a bearing therefore, a suction passage and a discharge passage extending through at least one of said members, said pintle member having suction and discharge notches connected to respective passages and connected to said chambers at their radially inner extremities, a substantially cylindrical bearing surrounding the pistons, said bearing being oscillatably trunnioned to the casing for movement on an axis approximately perpendicular to the rotational axis of said rotor member, said bearing being movable on said rst mentioned axis from a zero charged into the other of said passages and an operative'- connection between said bearing and said pintle member whereby they move in unison on the rst mentioned axis and the third mentioned axis, respectively, said bearing@ being in said zero discharge position thereof when said pintle member is approximately half-way between said positions thereof.

2. An hydraulic pump according to claim 1, wherein actuating means are connected to the bearing for oscillating it on the rst mentioned axis.

3. An hydraulic pump according to claim 1, wherein said operative connection is characterized by interengaged gear means on the bearing and pintle.

4. An hydraulic pump comprising a rotor member having a plurality of substantially radial pump chambers, pistons slidably fitted in respective chambers in substantially fluid tight engagement therewith, a pintle member, ..6 sleeved within the rotor member to afford a bearing,

therefor, a suction passage and a discharge passage through said pintle member, said pintle member havingy diamctrically disposed suction notches connected to the inner ends of the chambers and to one of said passages and said pintle member having diametrically opposed discharge notches connected to the inner ends of the chambers and to the other of said passages, a cylindrical bearing oscillatably trunnioned on an axis approximately perpendicular to the rotational axis of said rotor member and movable from a zero discharge position of said bearing whereat the bearing is substantially coaxial with said rotational axis to positions at opposite sides of said zero discharge position, said pintle member being rotatable approximately 90 on an axis substantially coaxial with said rotational axis to reverse flow of uid through said passages and an operative connection between the bearing and said pintle member whereby they move in unison, said bearing being in said zero discharge position when said pintle member is rotated approximately 45 during reversal of said ow of iluid.

5. An hydraulic pump according to claim 4, wherein the operative connection between the bearing and pintle member is characterized by gear means.

6. An hydraulic pump according to claim 4, wherein an actuator is connected to the bearing for oscillating it on the rst mentioned axis and thereby rotating the pintle member on its axis.

References Cited in the file of this patent UNITED STATES PATENTS 2,420,806 Anderson May 20, 1947 FOREIGN PATENTS 3,827 Great Britain 1914 434,961 Germany 1924 565,043 vGreat Britain 1944 

